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NASA’s James Webb Space Telescope (JWST) continues to discover galaxies too big to exist, scientists claim.
Six of these star clusters are far too massive to be of age, which their data puts them at between 500 and 700 million years old.
This means that unless the data was analyzed incorrectly, there is still something fundamental to learn about how galaxies formed after the Big Bang.
“If the masses are right, we’re in uncharted territory,” said study author Dr. Mike Boylan-Kolchin of the University of Texas at Austin.
One theory is that the universe expanded much faster after the big bang than is now believed.
Six galaxies (pictured) spotted by JWST are far too massive to be of the age their data suggests, which is between 500 and 700 million years old
Graph showing the relative amount of atoms (y-axis) in galaxies with at least a certain mass (M*) of stars (x-axis). Three galaxies detected by the JWST (black square) seem to use a much larger number of available gas atoms for stars than expected
The $10 billion JWST, which returned its first official images last July, is designed to detect light from the earliest stars and galaxies.
The farther away an object is, the further back in time it looks, because it takes longer for light to reach its 21-foot-tall (6 m) mirror.
It is the world’s largest and most powerful orbital space telescope and can look back 100 to 200 million years after the Big Bang.
In February, scientists at Australia’s Swinburne University of Technology analyzed the data collected six galaxies.
They estimated the age of the first one they looked at at about 13.8 billion years, but the light JWST detected had taken 13 billion years to reach it.
This meant that what they observed was a picture of what it looked like when the universe was only 700 million years old — barely 5 percent of its current age.
However, this photo also showed that it was made up of 100 billion stars – the same number as today’s Milky Way, which had 13 billion years to grow.
It was a similar story for the five other galaxies, where they contain far more stars than would be predicted for a cluster their age.
For a follow-up study, published in Nature Astronomy last week Dr Boylan-Kolchin ‘tested’ these results against the ‘ΛCDM cosmological model’.
This is a framework for understanding the role of dark energy (Λ) and cold dark matter (CDM) in shaping the evolution of the universe.
The astronomy professor discovered that with this model galaxies of this size and age are theoretically possible, but at an ‘absolute upper limit’.
In February, scientists analyzed the data it had collected on six galaxies. They estimated the age of the first one they looked at at about 13.8 billion years, but the light JWST detected had taken 13 billion years to reach it. This meant that what was observed was a picture of what it looked like when the universe was only 700 million years old – barely 5 percent of its current age. However, this photo also showed that it was made up of 100 billion stars – the same number as today’s Milky Way, which had 13 billion years to grow. Pictured: the six massive galaxies and their surroundings in the sky
Galaxies form when clouds of gas collapse under their own gravity, getting denser and hotter and eventually forming stars.
But some of this gas may be lost as it is expelled during the star formation process, or stripped away by an external force, such as a nearby supernova.
“Normally we see up to 10 percent of the gas turned into stars,” said Dr Boylan-Kolchin.
However, for these six galaxies to grow as large as they have been in existence, they have to have converted nearly 100 percent of their available gas into stars.
Dr. Boylan-Kolchin added: “While 100 percent conversion of gas into stars is technically right on the edge of what is theoretically possible, it really requires something very different from what we expect.”
This means that the ΛCDM model, which cosmologists have relied on since the late 1990s, may not be entirely correct.
The $10 billion JWST (pictured), which returned its first official images last July, is designed to detect light from the earliest stars and galaxies
Dr. Boylan-Kolchin said. “We need something completely new about the formation of galaxies or a change in cosmology.
‘One of the most extreme possibilities is that shortly after the big bang the universe expanded faster than we predict, which may require new forces and particles.’
Therefore, the model may need to be adjusted to account for these new, faster galaxy formation processes.
It could also be that there was more matter available for the formation of stars and galaxies before the universe began, which the model should also take into account.
But before scientists change their fundamental approach to cosmology, the data from the JWST needs to be confirmed as correct.
It is possible that supermassive black holes have heated up the gas around the galaxies, making them appear larger than they are.
The light the JWST detected also may not have originated as far back as 13 billion years, meaning it could show the galaxies at a later age.
As light travels through expanding space, its wavelength is stretched and its frequency lowered, through what’s known as “redshift.”
The size of the redshift allows scientists to calculate when the light was emitted from a star, but it can be affected by dust and give the wrong age.
It is hoped that further research will reveal whether this is the case.
Dr. Boylan-Kolchin wrote, “If analysis of JWST data continues to reveal the presence of strikingly massive galaxies in very early cosmic epochs, more exciting surprises lie ahead for the fields of galaxy formation and cosmology.”